Tubular structural member for exterior of construction machine

Abstract

To provide a pipe member being able to reduce the vibration applied and improve its durability. A pipe member to be installed on the body of a construction machine has an outer main pipe and an inner auxiliary pipe inserted into the outer main pipe. An outer diameter of the inner auxiliary pipe is formed smaller than an inner diameter of the outer main pipe. The inner auxiliary pipe has a securing part secured on the outer main pipe and at least one of end parts of the inner auxiliary pipe is a free end without being secured on the outer main pipe.

The invention claimed is: 
     
       1. A pipe member to be installed on a body of a construction machine, comprising:
 an outer main pipe; and an inner auxiliary pipe entirely inserted into the outer main pipe; 
 wherein an outer diameter of the inner auxiliary pipe is formed smaller than an inner diameter of the outer main pipe; and 
 wherein the inner auxiliary pipe has a securing part secured on the outer main pipe and at least one end part of the inner auxiliary pipe is a free end without being secured on the outer main pipe, and an axial length of a non-secured portion of the inner auxiliary pipe extends from the securing part to the free end is configured to be a length that allows the inner auxiliary pipe to vibrate at a frequency different from that of the outer main pipe when vibration is applied to the pipe member. 
 
     
     
       2. The pipe member of  claim 1 , wherein a part of outer peripheral surface on the free end side of the inner auxiliary pipe comes into contact with an inner peripheral surface on the outer main pipe. 
     
     
       3. The pipe member of  claim 1 , wherein an axial length of not-secured part extending from the securing part to the free end of the inner auxiliary pipe is twice or more as much as outer diameter of the inner auxiliary pipe. 
     
     
       4. The pipe member of  claim 1 , wherein the outer main pipe has a straight part extending straight from the securing part toward an axial direction on one side; and
 wherein the axial length of not-secured part extending from the securing part to the free end of the inner auxiliary pipe is half or more as much as axial length of the straight part. 
 
     
     
       5. The pipe member of  claim 1 , wherein the outer main pipe has two fixed parts to be fixed on the body of the construction machine; and
 wherein the inner auxiliary pipe extends from a first fixed part of the at least two fixed parts of the outer main pipe and extends perpendicularly to a second fixed part of the at least two fixed parts of the outer main pipe. 
 
     
     
       6. The pipe member of  claim 1 , wherein the outer main pipe and the inner auxiliary pipe are secured at the securing part by plastic deformation processing or welding processing or by securing with bolts or rivets. 
     
     
       7. The pipe member of  claim 1 , wherein the pipe member is installed on the construction machine as a handrail member, fence member, or support member supporting a mirror or antenna. 
     
     
       8. The pipe member of  claim 1 , wherein the inner auxiliary pipe includes first inner auxiliary pipe inserted into one end part of the outer main pipe and second inner auxiliary pipe inserted into other end part of the outer main pipe.